[vlc-devel] vlc_math.h ?

[Francois Cartegnie]

Le 11/12/2015 11:22, Rémi Denis-Courmont a écrit :
> Le 2015-12-11 00:59, Francois Cartegnie a écrit :
>> I need log2 and log2_ceil which are already duplicated in some modules:
> 
> log2 is a standard function so you can use it, so I fail to see why you
> would need to wrap that.
> log2_ceil is best implemented with clz family of functions, rather than
> floating point maths.
> 

moving

static inline uint8_t vlc_log2( uint32_t val )
{
    return 31 - clz(val);
}

static inline uint8_t vlc_ceil_log2( uint32_t val )
{
    uint8_t n = vlc_log2( val );
    if ((1U << n) != val)
        n++;
    return n;
}

in vlc_common.h might be the simpliest.

Francois